Objective to study the effect of SudanⅠ,Ⅲ,Ⅳ on the growth of SGC-7901.The change of DNA content is determined with Flow Cytometry,and the cell cycle is analyzed.Results show that the average content of DNA decreases in G_1 phase and increases in S and G_2 phase.The index of PI and SPF increase.It is indicated that SudanⅠ,Ⅲ,Ⅳ accelerate the cell cycle from G_1 phase to S and G_2 phase.It is also shown that the effects on SGC-7901 by Sudan Ⅲ in the dose of 50 μg·mL~(-1) and by SudanⅠ,Ⅳ in the dose of 10μg·mL~(-1) is very effective(P0.01).It is concluded that SudanⅠ,Ⅲ,Ⅳ affect SGC-7901 cell cycle to advance its differentiation and proliferation.